(drag corner nub) Resize and keep proportions

`↑ Shift` + `Mouse movement`

All hotkeys for Paint.NET

UI and Canvas Controls Pan image	`Space` + `Mouse movement`
UI and Canvas Controls Scroll up	`Page Up`
UI and Canvas Controls Scroll up	`Mouse wheel up`
UI and Canvas Controls Scroll down	`Page Down`
UI and Canvas Controls Scroll down	`Mouse wheel down`
UI and Canvas Controls Scroll left	`↑ Shift` + `Mouse wheel up`
UI and Canvas Controls Scroll left	`Shift` + `Page Up`
UI and Canvas Controls (twice) Scroll image to top left of editing window	`Home`
UI and Canvas Controls Scroll right	`↑ Shift` + `Mouse wheel down`
UI and Canvas Controls Scroll right	`Shift` + `Page Down`
UI and Canvas Controls (twice) Scroll image to bottom right of editing window	`End`
UI and Canvas Controls Scroll top left image to center screen	`Ctrl` + `Home`
UI and Canvas Controls Scroll bottom right image to center screen	`Ctrl` + `End`
UI and Canvas Controls Zoom in / out	`Ctrl` + `Mouse wheel up and down`
View menu Zoom out	`Ctrl` + `-`
View menu Zoom in	`Ctrl` + `+`
View menu Actual size	`Ctrl` + `0`
View menu Zoom to window	`Ctrl` + `B`
Options in the View menu Pan canvas	`Space` + `Mouse left click`
Options in the View menu Pan canvas	`Space` + `← ↑ → ↓`
Options in the View menu Pan canvas x10	`Space` + `Ctrl` + `← ↑ → ↓`
Edit menu Deselect active selection	`Ctrl` + `D`
Edit menu Deselect active selection	`⤶ Enter`
Shape tool Move Shape by 1px	`← ↑ → ↓`
Shape tool Move Shape by 10px	`Ctrl` + `← ↑ → ↓`
Options in the View menu Show menu. Press underlined letter in menu to use menu hotkey	`Alt`
Options in the View menu Show / hide Tools window	`F5`
Options in the View menu Show / hide History window	`F6`
Options in the View menu Show / hide layers window	`F7`
Colors window Toggle visibility of the window	`F8`
Text tool Commit text to layer	`Esc`
Magic Wand tool (x4) Activate Magic Wand	`S`
Paint bucket Activate Paint Bucket	`F`
Paint Brush Activate Paintbrush tool	`B`
Pencil tool Activate Pencil tool	`P`
Clone Stamp tool Activate Clone Stamp tool	`L`
Text tool Activate Text tool	`T`
Shape tool (x2) Activate Shape tool	`O`
Move tools (x2) Move Selection tool	`M`
Zoom tool Activate zoom tool	`Z`
Pan tool Activate Pan tool	`H`
Gradient tool Activate Gradient tool	`G`
Eraser tool Activate Eraser tool	`E`
Color picker Activate color picker	`K`
Recolor tool Activate Recolor tool	`R`
Image list and image navigation Next image	`Ctrl` + `⭾ Tab`
Image list and image navigation Previous image	`Ctrl` + `↑ Shift` + `⭾ Tab`
Image list and image navigation ... to <keybs>9</keybs>: Switch to image number pressed	`Ctrl` + `1`
Image list and image navigation ... to <keybs>9</keybs>: Switch to image number pressed	`Alt` + `1`
Toolbar Open File menu	`[`
Toolbar New image	`]`
Toolbar Open image	`Ctrl` + `O`
Toolbar Close image	`Ctrl` + `W`
Toolbar Close image	`Ctrl` + `F4`
Toolbar Save image	`Ctrl` + `S`
Toolbar Save image as	`Ctrl` + `↑ Shift` + `S`
Toolbar Print	`Ctrl` + `P`
Toolbar Exit Paint.net	`Alt` + `F4`
Toolbar then <keybs>X</keybs>: Exit Paint.net	`Alt` + `F`
Edit menu Open Edit menu	`Alt` + `E`
Edit menu Undo	`Ctrl` + `Z`
Edit menu Redo	`Ctrl` + `Y`
Edit menu Cut	`Ctrl` + `X`
Edit menu Cut	`↑ Shift` + `Del`
Edit menu Kopyala	`Ctrl` + `C`
Edit menu Kopyala	`Ctrl` + `Insert`
Edit menu Copy merged	`Ctrl` + `↑ Shift` + `C`
Edit menu Paste	`Ctrl` + `V`
Edit menu Paste	`↑ Shift` + `Insert`
Edit menu Paste into new layer	`Ctrl` + `↑ Shift` + `V`
Edit menu Paste into new layer	`Ctrl` + `Alt` + `V`
Edit menu Erase selection	`Del`
Paint bucket Fill area with primary color	`⬅ Backspace`
Edit menu Invert selection	`Ctrl` + `I`
Edit menu Select all	`Ctrl` + `A`
View menu Open view menu	`Alt` + `V`
View menu Zoom to selection	`Ctrl` + `↑ Shift` + `B`
Image menu Open image menu	`Alt` + `I`
Image menu Crop to selection	`Ctrl` + `↑ Shift` + `X`
Image menu Resize	`Ctrl` + `R`
Image menu Canvas size	`Ctrl` + `↑ Shift` + `R`
Image menu Rotate 90° (clockwise)	`Ctrl` + `H`
Image menu Rotate 90° (counter-clockwise)	`Ctrl` + `G`
Image menu Rotate 180°	`Ctrl` + `J`
Image menu Flatten	`Ctrl` + `↑ Shift` + `F`
Layers menu Open Layers menu	`Alt` + `L`
Layers menu Add new layer	`Ctrl` + `↑ Shift` + `N`
Layers menu Delete layer	`Ctrl` + `↑ Shift` + `Del`
Layers menu Duplicate layer	`Ctrl` + `↑ Shift` + `D`
Layers menu Merge layer down	`Ctrl` + `M`
Layers menu Rotate / zoom	`Ctrl` + `↑ Shift` + `Z`
Layers menu Layer properties	`F4`
Clone Stamp tool Set source point	`Ctrl` + `Mouse left click`
Adjustments menu Open Adjustments menu	`Alt` + `A`
Adjustments menu Auto-level	`Ctrl` + `↑ Shift` + `L`
Adjustments menu Black&White	`Ctrl` + `↑ Shift` + `G`
Adjustments menu Brightness / contrast	`Ctrl` + `↑ Shift` + `T`
Adjustments menu Curves	`Ctrl` + `↑ Shift` + `M`
Adjustments menu Hue / saturation	`Ctrl` + `↑ Shift` + `U`
Adjustments menu Invert colors	`Ctrl` + `↑ Shift` + `I`
Adjustments menu Levels	`Ctrl` + `L`
Adjustments menu Posterize	`Ctrl` + `↑ Shift` + `P`
Adjustments menu Sepia	`Ctrl` + `↑ Shift` + `E`
Effects menu Open Effects menu	`Alt` + `C`
Effects menu Repeat last effect	`Ctrl` + `F`
Settings dialog Open Settings dialog	`Alt` + `X`
Help menu Open Help menu	`Alt` + `H`
Help menu Online documentation	`F1`
Help menu Paint.net search page	`Ctrl` + `E`
Colors window Swap primary and secondary colors	`X`
Colors window Switch active color	`C`
Selection tools (except Magic Wand) Create a selection	`Mouse movement` + `Mouse left click`
Selection tools (except Magic Wand) Create a selection	`Mouse movement` + `Mouse right click`
Selection tools (except Magic Wand) Add to selection	`Ctrl` + `Mouse movement` + `Mouse left click`
Selection tools (except Magic Wand) Subtract from selection	`Alt` + `Mouse movement` + `←`
Selection tools (except Magic Wand) Invert selection mode	`Ctrl` + `Mouse movement` + `→`
Selection tools (except Magic Wand) Intersect selection modu	`Alt` + `Mouse movement` + `→`
Move tools (drag corner nub) Resize and keep proportions	`↑ Shift` + `Mouse movement`
Line / Curve tool (drag four way arrow icon) Drag entire line / curve	`Mouse left click`
Magic Wand tool Subtract from selection	`Alt` + `Mouse left click`
Magic Wand tool Invert a portion of selection	`Ctrl` + `Mouse right click`
Magic Wand tool Intersect selection mode	`Alt` + `Mouse right click`
Shape tool (drag nub) Move Shape nubs	`Mouse movement`
Shape tool (drag four-way arrow icon) Drag entire shape	`Mouse movement`
Shape tool Rotate Shape	`Mouse movement`
Shape tool (hold while clicking - or + corner size keys in the toolbar) Increase corner value change to 5px (Rounded Rectangle only)	`Ctrl`
Recolor tool Recolor primary with secondary	`Mouse right click`
Zoom tool Pan while zoomed	`Mouse movement`
Zoom tool Pan while zoomed	`Mouse wheel up and down`
Pan tool Pan the canvas	`Mouse left click` + `Mouse right click` + `← ↑ → ↓`
Paint bucket Fill area with secondary color	`↑ Shift` + `⬅ Backspace`
Shape tool (hold while rotating) Lock rotation to 15° increments	`↑ Shift`
Line / Curve tool Start Cap style	`,`
Line / Curve tool Line style	`.`
Line / Curve tool End Cap style	`/`
Shape tool (click and hold the nub) Move Shape nubs	`Mouse left click` + `← ↑ → ↓`
Shape tool Draw shape in secondary color	`Mouse left click` + `→`
Shape tool Cycle forward through shapes	`A`
Shape tool Cycle backward through shapes	`↑ Shift` + `A`